Madison was being held on $1,535,000 bond in the St. Lucie County jail.

Mascara said the charges involve two girls under the age of 18, adding that Madison's crimes were reported to police on Thursday night, and the investigation is still ongoing.

"We believe there may be additional victims," Mascara said. "I want to ask parents of Mr. Madison's female students to talk with their daughters. I encourage victims to contact sheriff's detectives at 772-462-3230."

Authorities said the sexual performance charge relates to a sexual encounter recorded by Madison and stored on one of his computers, Mascara said. Detectives seized several of Madison's computers and storage devices, which are being examined for additional evidence.

Detectives also arrested Madison's girlfriend, Janifer Thomas, 35, on Friday. She has been charged with being an accessory after the fact and failure to notify law enforcement of knowledge of a suspect of child abuse.

Thomas was released Saturday morning after posting bail on $18,750.

"Detectives worked around the clock to gather evidence and prepare documentation for arrest warrants, which were signed by Circuit Court Judge Lawrence Mirman," Mascara said. "I would like to thank the members of the U.S. Marshals Service for their invaluable assistance in helping our detectives locate and arrest the suspects in St. Lucie County."